Yaskawa GPD503 Drive - Manual (Page 40)

2.8 DC INJECTION BRAKING
A. Sn-04: Operation Mode Select 1 Digits 3 & 4 [ X X X X ] : Motor
Stopping Method Selection
Factory setting: 0 0 X X
Cn-12: DC Injection Time at Stop Factory setting: 0.0 sec
Range: 0.0 - 25.5 sec
When full range DC injection braking stop is enabled (Sn-04 = 1 0 X X), DC injection
braking is used to stop a motor more quickly than normal coast to stop, without the need
for braking resistors. When a STOP command is issued, there is a 0.5 second time delay
to apply DC to two phases of the motor’s stator winding. Then DC injection current is
applied. The duration of DC braking is a time period proportional to Cn-12 (at 10% output
frequency) and the level of output frequency at the time the STOP command is issued.
Braking torque is 50-70% of full load motor torque.
EXAMPLE:
Cn-12 = 0.5 sec (at 10% output)
Braking time at Fmax (100% output frequency) = 10 x 0.5 = 5 sec
Full Range DC Injection Braking Stop Sequence
RUN CMD
OUTPUT
FREQUENCY
STOP
0.5 sec
COASTING
DC BRAKING TIME
Cn-12 x 10
DC IN-
JECTION
BRAKING
TIME
Cn-12
0 10% 100%
OUTPUT FREQUENCY
AT TIME OF STOP COMMAND
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